This application requests funds to establish a Fragile X Research Center, the focus of which is family adaptation to fragile X syndrome (FXS). Eleven investigators from six disciplines (anthropology, developmental psychology, special education, speech and hearing sciences, quantitative psychology, psychiatry), based at two Mental Retardation and Developmental Disabilities Research Centers (the University of North Carolina at Chapel Hill and the University of Kansas), are collaborating on an integrated and longitudinal study. A core sample of 100 families will be assessed on three occasions over a five-year period of time, and data from these and other families will form the basis of three projects. Project I (Parent and Family Well-being in FXS) focuses on the extent to which mothers and fathers of children with FXS experience a positive quality of life, are hopeful about the future, and are protected from or experience adverse mental health outcomes such as depression, anxiety, anger, and stress. Project II (Maternal Responsivity and the Development of Children with FXS) examines the extent to which parental style may be impacted by the challenges associated with FXS children, and what parental and child factors may account for disrupted patterns of parental responsivity that themselves may further exacerbate the language and cognitive development of FXS children. Project II also examines the extent to which "low" parental responsivity in some families can be reversed by intervention. Project III (Family Adaptation to Temperament and Challenging Behavior in FXS) focuses on how parents respond to their child's challenging behaviors. The project is based on research documenting a wide array of challenging behaviors in FXS (hyperarousal, attention deficit, hyperactivity, anxiety, behavior problems, autistic behaviors, self-injury) and the assumption that although these behaviors have a biological basis, parents play important roles in the extent to which these behaviors are expressed and regulated. Two new cores (Administration, Data Collection) and an existing MRDDRC Core (Design and Statistical Computing) will support each project to assure coordination and integration of efforts and maximize cost-efficiency. [unreadable] [unreadable]